From: Lorenz Bauer lmb@cloudflare.com
commit 8bec4f665e0baecb5f1b683379fc10b3745eb612 upstream.
The reuseport tests currently suffer from a race condition: FIN packets count towards DROP_ERR_SKB_DATA, since they don't contain a valid struct cmd. Tests will spuriously fail depending on whether check_results is called before or after the FIN is processed.
Exit the BPF program early if FIN is set.
Fixes: 91134d849a0e ("bpf: Test BPF_PROG_TYPE_SK_REUSEPORT") Signed-off-by: Lorenz Bauer lmb@cloudflare.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Reviewed-by: Jakub Sitnicki jakub@cloudflare.com Acked-by: Martin KaFai Lau kafai@fb.com Acked-by: John Fastabend john.fastabend@gmail.com Link: https://lore.kernel.org/bpf/20200124112754.19664-3-lmb@cloudflare.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- tools/testing/selftests/bpf/progs/test_select_reuseport_kern.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/tools/testing/selftests/bpf/progs/test_select_reuseport_kern.c +++ b/tools/testing/selftests/bpf/progs/test_select_reuseport_kern.c @@ -113,6 +113,12 @@ int _select_by_skb_data(struct sk_reusep data_check.skb_ports[0] = th->source; data_check.skb_ports[1] = th->dest;
+ if (th->fin) + /* The connection is being torn down at the end of a + * test. It can't contain a cmd, so return early. + */ + return SK_PASS; + if ((th->doff << 2) + sizeof(*cmd) > data_check.len) GOTO_DONE(DROP_ERR_SKB_DATA); if (bpf_skb_load_bytes(reuse_md, th->doff << 2, &cmd_copy,